I have a friend. who said in jail they made a "Fifi". Other institutions I'm sure have similar devices by other names.
I don't remember it's exact make up but basically:
A shampoo bottle
Cut off an end
Pack with paper towels to desired tightness
Lube up a sandwich bag and shove into the paper towels
Microwaving for warmth was done behind was often practiced but I would recommend EXTREME CAUTION if you even think about doing that.
After you're done you can discard the sandwich bag and have a virgin Fifi tomorrow.

Being an old Q has the benefit of wanking wisdom . Here's a oldie but a goodie you young`uns might not know bout . Getcha a nice fat cucumber . Set it out in the sun or microwave it a few seconds to warm it up a lil (Be careful not to get it hot enough to burn ya) . Now cut one end of it off with a knife ( or chainsaw if you prefer LoL) and with a small spoon scoop out the seed part of it (Forming a tunnel) . Keep the hole in the middle small . Now insert one erect penis & go to work ! Trust old Q your gonna love it !